I have a Vontage phone system here in the U.S. As long as I have a laptop, box and wireless equipment, I can use this system on any phone that plugs into a phone jack. I have used it in St. Kitts, Antigua and Anguilla. Will I be able to use it on AC?

That's Vonage, right? So do you have the extra "softfone" facility that assigns a phone number to your laptop? So that you then just use a headset plugged into the computer? (I take it you're using an internet connection, not a phone one). If you don't have "softfone", do you use one ethernet connection to connect to the internet and another ethernet connection (or a USB one with an adapter to make it into ethernet)?

In either case, if you're running a suitable VPN on the computer then it should work here. The problem arises when you don't have a computer interposed between your phone and the phone line, because then you can't introduce a VPN into the circuit and you're subject to the blocking nonsense we have here.